Internal-combustion engine.



'0. H. T. ALST ON & P. T. HOUSTON.

I INTERNAL COMBUSTION ENGINE.

APPLICATION FILED SEPT. 14, 1912.

Patented July 22, 1913.

2 N 2 SHEETS-SHEET 1..

0. H. T. ALSTON & P. T. HOUSTON.

INTERNAL COMBUSTION ENGINE. APPLICATION-FILED SEPT. 14, 1912.

1,068,379. Y Patented July 22,1913.

2 SHEETS*SHEET 2.

snares PATENT on-men CHARLES HENRY THOMAS ALs'roN AND PERCIVAL TURNERHousToN, or LONDON,

' ENGLAND. V

INTERNAL-COMBUSTION ENGINE.

Specification of Letters'Patent; Patented J ly 22, 1913 Applicationfiled September 14, 1812. Serial No. 720,426.

T 0 a1 Z whom it may concern.

Be it known that we, CHARLES HENRY THOMAS ALSTON, of 19 Audley House,Margaret street, London, England, and Panor- YAL TURNER HOUSTON, of;Lloyds avenue, London, .England, subjects of the- King of y reatBritain, have invented'certain new and useful Improvements Relating toInternal-Combustion Engines, of which the fol lowing is a specification.

This invention relates to internal combiis' tin engines, whether workingon the twocycle or four-cycle system, and especially to those used formarine propulsion. When a ship is in a heavy sea, the propellersometimes rises out of the water, thereby causing the engine to race. Itis necessary, therefore, to throttlelor otherwise control the engine atsuch times, and there follows then a danger that the engine may stopwhen the propeller reenters the water.

This invention has for its object the pre-. venting of such anaccidental stoppage of the engine.

It has been previously proposed to provide internal combustion engineswith a supply of compresed air, the pressure of which is slightly belowthe normal pressure 1n the cylinder following ignition, for the purposeof starting the engine and as the motive fluid should a mis'fire occur.In the latter casea mechanically operated valve is timed to open andclose during the power stroke and a non-return valve isheld closedagainst the air pressure by thenormal pressure in the cylinder followingignition, so that the air is prevented from entering the cylinder unlessthe ignition fails. The objection to this device is that when the amountof fuel introduced is below the normal, full charge (say for a lightload) the pressure of the air will exceed the internal pressure of thecylinder and will therefore gain admission; and if the pressure of theair is below the lowest internal pressure used, then the pressure willbe insufiic'ient to operate as the m0- tive fluid should the engine berunning ,with full load. Again, in the case of the ,Die-' sel type ofengine, the admission period of the compressed air for full load wouldbe too great for half load, and-if the period,

was shortened to the lightest load then the amount of compressed a1renterin the cyl inder should a misfireorcur would e msufliadmissiontionof its opening, and the pressure of the compressed air are so arrangedthat normally thepressure in the cylinder following ignition issuflicient at all loads to prevent a the entry of the compressed air tothe cylinder. When a misfire occurs, due tothrottlingor other cause, ora momentary falter of the engine takes place due to the reimmersion ofthe propeller, causing a momentary over-load, the compressed air will beable to gain admission and prevent or practically prevent a stoppage ofthe engine; The air isg or ma y be admitted on the firing stroke from asuitable receiver, and the ignition is timedto take place before thecompressed air valves are timed to open.

In some cases the valves referred to above may serve as the starting andreversing valves, and in engines of the Diesel type in'whichthe mairimumpressure varies little or not at all, it is sutficient to vary thecutoff of the compressed air only according to theload, keeping the airpressure approximately constant and rather lower than compressionpressure.

, By arranging the cutoff of the compressed air to take place earlierwith the less amount of fuel, and vice versathe liability of thecompressed air gaining admission" to the cylinder toward the end of theperiod of the air (owing to the falling expansion) is avoided; and forthis reason also the pressure of the compressed air for pressure in thecylinder due to thedifferent loads is arranged to be under controlsimultaneously, and would be higher with a late cut-off than with anearly cut-oft.

In the accompanying drawings F i ure 1 is a diagram illustrating thecontrolling mechanism. Fig. 2 is a section of'a combinedautomatic inletvalve and mechanically operated valve, Fig. 3 is ,a modifica- -tionthereof and Fig. 4 is n elevation of a cam cylinder for actuating themechanical va1ve. Figs. 5 and 6-ar'e diagrams respectively for aconstant volumecyclo and a constant pressure cycle (Diesel type).

Referring first to Figs. 2 and 3,"& is the autrgmatic inlet, valve and bis the mechanically-,operated valve, the latter being pref:

7 Nil erably of the equilibrium type. The stem of the valve a passesthrough and is free to slide in the stem 03 of the valve 6, a light coilspring e being mounted on' the stem 0 and acting between the nut f andthe v lve stem (1 as in Fig. 2, or the piston'end valve 6 as in Fig. 3in order to hold the valve (6 closed. A stronger spring 9 is arrangedaround the stem and serves tohold w ,the valve 6 closed unlessmechanically operated. h is the inlet for-compressed air which .issupplied from any-suitable source or reservoir. dis a tappet leverpivoted at i, one end In of which lever rests against an extension pieceZ of the valve stem d as in Fig.2 or against the piston end 6. of thevalve 1) itself asinFig, 3. The other end mof the talppet lever restsagainst a plunger n capab e of sl-idin in its casing n, the plungercarrying a roller or wheeln which runs uponthe surface of the camcylinder 0 when the latter is in its neutralposition and is actuatedby'the' cams 0 or 0 when the cam eylinderis i'novedlon 'itudinal'ly tobring either of the cams into t 1e path of the roller or wheel 11?. Thecams are of taper shape, such. as shown in Fig-.54, in order to enablethe supply of compressed air to'be variably opened and cut off atsuitable parts of the stroke of the engine.

The valve mechanism Works asfollows When the engine is running normallythe pressure in the cylinder is suflicient to hold the valve or closed;although'the valve?) is opened to admit compressed air at every? cycle,the'pressurc ofthe air isyregulated so that it is always lower than thepressure prevailing in the cylinder up 'to the point of cut off of theair and therefore the air" can not gain admission to the cylinder;jSimilarly, the cut-off of the compressed air; is arranged to preventtheadmission of com pressed air to the cylinder when the internalpressure falls (owing to the expansion of the gases) below that of thecom ressed air. Should a'fiiisfire occur, or if or' any reasonthe-internal pressure in the cylinder should prove insufficient toholdclosed the valve a when the air valve 6 is opened, then compressed airwould flow into the. cylinder and become the motive power to completethe stroke and insure the running,of the engine until the next firingstroke.

A suitable controlling mechanism is shown diagrammatically in Fig. 1. Ina suitableeasing 7) a cam slu ft 1' is mounted torotate and slide in s'itab e hearings and isrotated by suitable gearing, thc cam shaftcarrying the cam cylinders .0; one for each cylinder. Thc end of theshaft '2- is connected toan arm 8 fixed "on a shaft -and' another arm .9

5 lating' device) in the fuel supply pipe rug.

The lever o is also linked to a similar lever m which is adapted toregulate a pressure reducing valve 1 in the compressed air supply pipey. The shaft t is rocked by any suitable .means by hand, power, with.or; without the. agency of'a governor, or directly by such governor, anoperating arm.- 2 being shown fixed to the shaft t. In'the drawing thecam shaft is shown in the neutral or stop position-with the fuel supplythrottled or shut off at 10. Upon the cam shaft being slid to the rightor left, accord ing' to the direction of rotation desired (ahead orastern). the cams 0 or 0 are brought into the path of the roller orwheel a as before described and the engine is started by admittingcompressed air as is already known. V

- Thefuel valve w and pressure reducing valve 1 being actuated by theirconnections with the camshaft r, it follows that as the load varies sowill the amount of fuel and" the pressure of the compressed air beincreased or reducedin proportion, the duration of admission of the airsupply being lengthened or shortened correspondingly by the position ofthe cams with regard to the air valve tappet plunger at; In Fig. 5 a setof diagrams for an explosion type of engine indicating full load F, L,two thirds load 'I L, one third load 0, L, and light load IL L, aregiven in full lines, the dotted lines fl, t Z, 0 Z and Z Z indicatingthe correspondfng diagrams for the compressed air. In Fig. 6 a set ofdiagrams for a Diesel t-y e of 6 engine indicating full load F L,two-thirds loadhi L, and one-third load O-L, in full linesfonth'e fueland corresponding dia grams for the-compressed air f l, t Z and e}. Inthe example illustrated in Fig. 5,

the pressure of the compressed air is shown .to vary according to thedifferent internal:

; pressures and the supply of'compressed airis gcut-oif before theinternal pressure falls to that ofthe compressed air, whereas in theexample illustrated in Fig. 6 thepressure of the compressed air does notvary because the internal pressure remains apiproximatel constant butthe supply of compresse air is cut off before the internalpressure'falls to that of the compressed air. Hence it follows thatduring normal work--- ing no compressed air will be able to gainadmission to the cylinder except that small clearances-between thevalves a and .We claim z- 1.- Invan internal combustion engine, aworking cylinder, a pipe for supplying compressed air to said cylinder,a mechanically 125 operated valvecontrolling the compressed air supply,a non-return valve arranged to be acted on'by the air admitted by saidmechanically operated valve and held closed by the normal internalpressure in'the cylin-' 13o quantity which becomes trapped in the derfollowing ignition, controlling the opening'and closing of saidmechanically operated-valve, a pressure .re-

ducing valve inthe air supply pipe, a fuel supply pipe for saidcylinder, a fuel regulating valve in said fuel supply'pipe, con nect onsbetween said pressure reducing valve and said fuel regulating valve,.tocorrelate the action of the fomi'zerand the latter, the'cut offmechanism being operable to vary the duration of the opening of saidmechanically operated valve, and connections' between said cut offmechanism and pose set forth.

said first-named connections to correlate the actlon of said out offmechanism with relation to the fuel regulating valveand the pressurereducing'valve, as and for the pur- 2. In an internal combustion engine,a working cylinder, a pipe for supplying compressed operated valvecontrolling the compressed air supply a non-return valve arranged to beacted on-by the air admitted by said me chanically operated valve andheld closed by the normal internal pressure in the cylinder followingignition, out off mechanism controlling the opening and closing of saidmechanically operated valve and including a slidably adjust-able camcylinder having air to said cylinder, a mechanically out off mechanism ltapered cams thereon to determine the duration of the opening ofsaidmechanically operated valve, a. pressure .reoucing valve in the airsupply pipe, a fuel. supply pipe for said cylinder, a' fuel regulatingvalve in said fuel supply pipe, connections between said ressurereducing valve and said fuel reguating valve, to correlate the action.of the former and the latter, the cut off mechanism being operable tovary the duration ofthe opening of said mechanically operated valve, andconnectionsbetween said cut-off mechanism and said first namedconnections to correlate the action of said cut off mechanism withrelation to the fuel regulating valve and the pressure reducing valve,as and for the purpose set forth.

In testimony whereof We have hereunto set our hands in presence ofsubscribing witnesses I CHARLES HENRY THOMAS ALSTON.

PERCIVAL TURNER HOUSTON. \Vitnesses as to the sigi'iature of CharlesHenry Thomas Alston:

W. J NoR\voon, GEO. B. ERAKLIN.- Witnesses as to' the signature'ofPercival Turner Houston:

.B. G. I-IARRISOX,

Gnonon C. DOWNING.

Copies of this patent may be obtained for five cents each. by addressingthe Commissioner of Yatents,

Washington, D. C.

